An exhaust gas recirculation system (EGR system) is configured of a separate EGR valve and an EGR valve housing including the same, in which the EGR valve housing is fixed to an engine compartment.
The EGR valve is an apparatus which controls a re-circulated amount of exhaust gas. The EGR valve housing is configured so that the EGR valve may be inserted into and seated in the EGR valve housing. The EGR valve housing is further configured of a channel through which exhaust gas may be introduced and discharged and may be provided with a flange so that the EGR valve may be provided with a pipe connected to the channel. Further, the EGR valve housing may be provided with a boss and the flange so as to be connected to an intake and exhaust system.
However, the volume of the EGR valve housing is increased and thus it is difficult to choose a position of the EGR valve according to a layout of the engine compartment. The high temperature EGR gas is re-circulated through the EGR valve. In this case, to prevent the EGR valve from being damaged due to heat which may be generated in the EGR valve, the EGR valve needs to be provided with a separate cooling circuit and a cooling water channel for supplying cooling water to the cooling circuit. Further, providing the cooling circuit and the cooling water channel in the EGR valve housing leads to an increase in vehicle costs.